Internal-combustion engine



Oct. 25,1927. 1,646,789 M. GATT] INTERNAL comaus'now ENGINE Filed Julys. 1922 4 Sheets-Sheet 1 see; as 84 -4 ea I e l 80 v III/06.2mm o o H.

Oct. 25, 1927.

M. GATT! INTERNAL COMBUSTION ENGINE Filed July 5. 1922 4 Sheets-Sheet 2Oct. 25, 1927.

M. GATT] INTERNAL COMBUSTION ENGINE 4 Sheets-Sheet 3 Filed July 5. 1922I WWW w,

Oct. 25, 1927. M. GATTI INTERNAL COMBUSTION ENGINE Filed July 5; 1922 4Sheets-Sheet 4 Patented Oct. 25 1927.

UNITED STATES PATENT OFFICE- MARIO GATTI, 0F MILAN, ITALY.

INTERNAL-COMBUSTION ENGINE.

The present invention has for its object a two-stroke internalcombustion engine, which is designed to work by means of liquid fuel ofany class whatever.

The motive system in question is characterized by the fact that theworking cylinder so called is connected in a suitable way with asupplementary cylinder, the object of which is to furnish the scavenginair and to produce, at the same time, 'hig ly compressed air, which, bypassing through an 1njector, has the eli'ect of atomizing the liqu1dfuel which has been injected into it and which serves to start theengine working. This mixture, as a result of the high compression of,the air in the supplementary cylinder, and in consequence of a certainpressure etfected,'at the same time, in the main cylinder, will beignited spontaneously upon passing into the interior of this lattercylinder, where the process of combustion will be completed, either witha constant volume of fuel or at a constant pressure, according as theregulating organs of the engine are adjusted to produce, at a givenmoment, a rapid or slow opening of the injector.

Other special characteristics of the invention are formed by variousdevices and arrangements which are'intended to give and to ensure to theengine regular and economic working.

Among the accessories provision has been made for a particularlyimportant blowing apparatus, which will provide the air necessary forthe compressed air supplementary cylinder.

- The idea of the invention will be readily understood by referring tothe annexed drawings which show, by wa of example, some practical formof executlon of this invention.

According to these drawings:

Figs. 1, 2 and 3 are respectively a view in median-vertical section; asection drawn at right angles to the first; and a plan of the motivesystem, provided with cooling water circulation.

Figs. 4 and 5 give respectively a side view, partly in section, and amedian section drawn at right angles to the first, of a similar enginewith a cylinder provided with cooling vanes for same.

Fig. 6 shows in median section the detail of the upper part of theengine, in accordance with Figs. 1 and 3, in which the injector is seenfitted.

Figs. 7 and 8 show respectively a view in longitudinal section, and a,cross section alqr g the line .1:a: of the gtormer, of an engine,"inaccordance witlif fjltlie invention, having four cylinders.

Fig. 9 gives the detail of an arrangement applicable to the said enginesfor purposes of starting.

Figs. 10 and 11 show respectively a longitudinal section and a plan ofthe piston with which the blowing apparatus, which completes the motivesystem, is provided, and which serves, as has already been said, tofurnish air to the supplementary cylinder for purposes of compression.

Fig. 12 shows an alternative arrangement of the blowing apparatusreferred to; and

Fig. 13, finally, deals with a way whereby the rod of the workingcylinder properly so called, and that of the supplementary cylinder, maybe connected.

In the different figures the same or similar parts are indicated by thesame numerals.

As regards Figs. 1, 3 and 7, 8, the arrangement comprises, for eachworking cylinder 1, the centre of which is placed in a plane passingthrough the centre of the driving shaft, an auxiliary cylinder 3 ofsmaller dlameter, the centre of which is moved forwards relatively tothe centre of driving shaft 2 in the direction of rotation of thislatter. The two rods 4 and 5 of the two pistons which run in thecylinders 1 and 3 are both connected to the same crank pin 8; or, inorder to simplify the construction or design, the rod 5 of the smalleriston 7 may be connected up with the second rod 4 at any part whateverof this latter; as, for example, may be seen in Fig. 13, on a lug 9arranged on the rod 4.. In the couple of cylinders 1 and 3, the twopistons 6 and 7 are both compressors in the compression phase of theirwork, and motors in the combustion and expansion phases.

The larger diameter cylinder 1 is provided beneath with openings 10which open into the discharge tube 11, and above with openings 12 whichestablish connection with the smaller diameter cylinder 3, which, inturn, is provided beneath with openings 13 which communicate with theair inlet pipe. The smaller cylinder communicates above, by means of theconduit 15, with the injector connected, by means of a suitable nozzle,

with the retention valve 19 placed above the cylinder 1 at the side ofthe injector 16.

The larger diameter cylinders 1, and the smaller diameter cylinders 8,are fitted to a single body, provided with a water cooling jacket (Figs.1, 3 and 7, 8) or with radi- .-,-ation vanes 21 (Figs-'4:- and 5).

The air is driven into the cylinder 3 through the conduit 14 arid theopenings 13, by a blowing apparatus which is formed of a cylindricalbody 22 cast in one piece with the housing of the engine 23, and closedby a cover 24, the latter being provided with an opening 25 foradmission of air and which is regulated by means of the wing valve 26(Fig. 4). The piston 27 slides along in the interior of the body 22 ofthe blowing apparatus, and this piston carries the suction valve 28. Themovement of the piston 27 is controlled by the worm 29, which is keyedon to the driving shaft 2, and provided with an inclined groove 30(Figs. 1 and 5) in which the lower half of a flange 30 slides, whilstthe other half of it 'is enclosed in a plug fitted on the piston rod 27.The rod 31,fixed on the bottom of the body 22 and in the cover 24,traverses the radius of the piston rod, thus preventing the latter fromturning, whilst the rotation of the worm. 29 imposes an alternatingmovement on he piston 27' by the gliding action of the flange 30 in thegroove 30 The working of the suction valve 28 will be clearly understoodby an inspection of Fig. 10, in accordance with which the said valve,which is formed of a fine ring 32 of steel, fitted on the wall of thepiston 27 and provided with several pins 33, which pass through the saidwall and carry light springs 34. These springs force the ring valve togrip against the wall of the piston 27 and to bind the ports 25 intendedfor the passage of the air. I

Thismotive system is completed by a flywheel 36, an ordinary centrifugalregulator, a pump for the circulation of the water, if the engine iscooled by circulation of water, and another lubricating pump.

The working of the engine is as follows: When the crank has been turnedvabout 60 and before reaching the outer dead centre, the larger piston 6begins to open the exhaust openings 10, thus setting up a reduction ofpressure in the exhaust gases, which continues up to 95% of the outerstroke. At this point the pressure of the gases in the cylinder 1 hasconsiderably weakened, so much so as to permit the admission of thescavenging air, which passes from the blower through the pipe 14 and theopenings 13 into the small cylinder 3, whence it enters the largercylinder 1 through the openings 12 and the conduit 15. At this stage,the needle of the spraying nozzle 16 being raised, communication between15 and 1 is free.- The residuary gases of combustion will thus beexpelled from the cylinder 1 through the opening 10 and the pipe 11. Thecrank, on continuing its rotation, and when it has reached about 60,above the outer dead centre, compels the two pistons 6 and 7 to closethe openings 10 and 12, at the same instant. At this juncture thecompression phase, which is common to the two cylinders 1 and 3, begins,and at the same time the nozzle of the injector 16 is lowered, with theresult that communication between the cylinders 1 and 3, through theconduit 15, is interrupted, the only avenue of communication remainingopen being that'through the opening 12. The cylinders 1 and 3 willremain in reciprocal communication up to the moment in which the smallerpiston 7 reaches the height of the openings 12, after which, the saidopenings being closed by 7, the two cylinders will be no longer inreciprocal communication one with the other, and the compression willcontinue separately in them for the remainder of the stroke of thepistons 6 and 7 right up to the dead centre. Meanwhile the fuel pump 18will have delivered the required quantity of fuel to the lower sectionof the injector 16. Owing to the arrangement applied. the piston 7 ofthe small cylinder 3 will be at the upper dead centre; that is to say inthe position of greatest compression, when the large piston 6 has passedthe dead centre by some degrees; and as the smaller cylinder 3 has avery small compression chamber, much smaller than that of the largecylinder 1, the quantity of air enclosed by the small piston 7-beyondthe openings 12 will attain a compression the extent of which is two orthree times greater than that which has been produced in the largercylinder. When the piston 7 has completed its compression stroke,introducing into the cylinder 3 the quantity of highly compressed air ofwhich mention has been made above, the cam 17' will raise the nozzle ofinjector 16, whereupon the air, which has been compressed to the fullestpossible extent in the small cylinder 3, will rush through the conduit15 into the injector 16, passing from the latter into the large cylinder1 and carrying with ,it the thus highly atomized fuel, which has I beendelivered into the injector 16 by the pump lS. This :t'uel mixture, uponentering the cylinder 1, will ignite immediately and completely, thanksto the high temperature existing in the cylinder 1, owing to thecompression of the air, and the temperature of the super-pressure air inthe cylinder 3, forming part of the mixture itself.

When opening the injector 16 quickly, the injection is effectedinstantaneously, whic gives rise to combustion at a constantvolumc. If,on the contrary, it is desired to obtain combustion at a pressure nearlyconstant, it will be necessary suitably to regulate the manner oflifting the injector nozzle.

The type of the engine which has just been described and which is shownin the drawings, otters considerable advantages over either single ortwo-stroke engines.

In fact, comparing this engine with the Diesel motors, it is muchsuperior by reason of the fact that it utilizes, by injection, heatedair, which faciltates combustion; that it dispenses with the specialcompressor for the air to be injected; and. that it calls for a smalleramount of energy for the production of the compressed air, as noquantity of heat is dissipated.

As regards two-stroke engines, this new type of engineptfers thefollowing advantages: complete introduction of the fuel mixture and evensuperfeeding, should the regard to the fuel.

needarise, in accordance with the capacity of the blower; more perfectscavenging, as this is procured in the direction of the exhaust currentitself and during a longer interval; more time, available for thedepression of the exhaust gases; closing. of the inlet and outletopenings at the same moment and, if this should be necessary, a retardedclosure of the inlet as compared with theoutlet, in order to realizesuper-feeding. All' this remains in the fraction of stroke of theordinary two-stroke engines.

The fuel injector 16, used in the engine which forms the object of thisinvention, is formed (Fig. 6) of a rod 37 which closes the mouth of theconduit towards the large cylinder 1. In this rod a small rod 38 slidesand on the latter thespring 39 which is placed inside the rod 37 acts.-This arrangement of the two rods 37 and 38 allows of the secure closureon their seats, of the rod 37 in regard to the air,and of the rod 38 inlivered by the pump 18, issues from the retention valve 19 and isdeposited in the chamber 40. On the opening of the in jector, the rod37, as soon as it has been lifted from its seat by several tenths of amillimetre, jection, the head 41 of the small rod 38 so as to lift it.At this moment the air, which has first been introduced into thechamber. by 15, will inject the fuel into the compression chamber of thecylinder 1 as a result of the lifting of 37.

In Fig. 12 there is shown a modified arrangement of the blower which, inthis case, is provided with the double effect cylinder 22 and is drivenfrom-the piston 27' by means of cranks on a small separate shaft 42which is driven by gearing.

" 1, it does not The fuel, which is dewill touch, by means of a pro,

In Fig. 7, the blowing set is shown mounted on the extension of thedriving shaft 2 and is. composed of two apparatus, each of doubleeffect, with the corresponding pistons-driven by the worm, ashas beendescribed above.

Fig. 8 shows, on one side, the arrangement of the cam shaft 43 whichdrives the injectors 16 and the fuel pumps 18, whilst, on the oppositeside, the four blown air pipes coming from the set are seen.

In the types of engines, such as those to which this invention applies,starting by hand, if it can be done in machines of limited power, isdifficult to eflect when it is a matter of motors of somewhatconsiderable dimensions, owing to the high degree of compression whichis 1 obtained in these engines. In such cases recourse may be had to oneof the ordinary compressed air systems,'hitherto used in practice, or tothe special arrangement which we are about to describe and which isshown in Fig. 9. The said arrangement comprises a chamber 44, incommunication with the compression chamber of the large cylinder 1, bymeans of the pipe 45; a ball valve 46, carried by the finely-screwed rod47, and driven by the crank 48, allows of establishing orbreakingcommunication of the chamber 44 with the cylinder 1. Thecapacity of the chamber 44 is suchthat, with that of the cylinder allowof exceeding the degree of compression of 4 and 5; In the saidchamber,44 there is fitted a retention valve 48, bra'noh connected witha three-way cock lace'd on the pressure pipe of the fuel pump. 11 49there is arranged a lighter which is formed of an electric candle or ofa sprin arrangement, the indented barrel .50 of whic rubs against apiece of cerium iron 51 and produces a spar 52, is driven by jectorworking.

As regards starting, lows:

with the assistance of the lever 48 the valve 46 is opened; thethree-way fuel cock is-turned in the direction towards the retentionvalve 48 of the chamber 44, instead of directing it towards that of theinjector.

The electric light or the lighting arrangement of cerium iron isattached; and for the the rod which starts the inthe method is asfolcrank 53 the engine is turned. In this manthe engine starts workingat a low pressure. At the moment the engine has reached the correctworking speed, the three-way cock is turned and the fuel is delivered tothe injector, instead of its being sent to the cham- The spring bolt,fitted at her 44. Then the lever 48 is turned and the valve 46 isclosed, so as to cut E the chamber 44, and it is at this juncture thatthe engine will begin to work at high compression and the lighting willbe cut off either by hand or automatically. The chamber 44 is providedwith a pipe 54 which runs along the cylinder 1 up to the height of theexhaust openings, this being intended to facilitate the'cleaning of thesaid chamber 44. It is understood that the detailsv of constructionture. arranged in communication with the.

working cylinder, a scavenging air supply communicating with the medialportion of the auxiliary cylinder, a piston for the auxiliarycylinderincluding a head and a rod, the rod of the piston of the auxiliarycylinder being connected to the rod of the piston in the workingcylinder in such manner that the head of the piston in the auxiliarycylinder acts at lower dead center as a valve to control the passage ofscavenging air from the scavenging air supply to the working cylinder,substantially as and" for the pur poses set forth.

2.A" two-stroke internal combustion engine as claimed in claim 1,wherein the connections of the rod of the piston of the auxiliarycylinder with the rod of the piston of the working cylinder is arrangedat a slight angle, so that the piston of the auxiliary cylinder will bevat upper dead center when I the piston of "the Working cylinder haspassed the dead center.

3. A two-stroke internal combustion engine as claimed in clai'ml,wherein the point of c ommunicationbetween the two cylinders is arrangedat'the top ofthe working cylin der but short of the top of the auxiliarycylinder to permit of supercompression of air in the upper part of theauxiliarycylinder, means for establishing communication between theextreme upper ends of both of said cylinders, an injector for furnishingliquid fuel positioned on top of the working cylinder, so that thesupercompressed air from the auxiliary cylinder will pass therethroughas it enters the working cylinder-so asto be thoroughly mixed with thefuel.

4. A two-stroke internal combustion en-- ,gine as claimed in claim 1,wherein the point of communication between the twocylinders is arrangedat the top of the working cylinder butshort of the top of the auxiliarycylinder to permit of super-compression of air in the upper part of theauxiliary cylinder, means for establishing communication between theextreme upper ends of both of said cylinders, an injector for furnishingliquid fuel positioned on top of the working cyl'nder,, so that. thesupercompressed air I from the auxiliary cylinder will pass therethroughit' enters the working cylinder so as to be thoroughly mixed with thefuel, means for operating the injector including a cam rotatable withthe main shaft of the engine, and a system of levers coacting with thecam for ensuring of the passage of compressed air from the auxiliarycylinder through the injector and thence. into the main cylinder intimed relation with the operation of the mainjc ylinder.

MARIO GATTI.

